The field of the invention relates to a handling apparatus. In particular, the invention relates to an equipment handling apparatus such as a pallet mover, with a machine frame and with an extension arm, movable in the vertical direction, on which is provided an engaging element for engaging a workpiece or another object to be handled.
A conventional handling apparatus, as exemplified by U.S. Pat. No. 4,362,454, includes a gantry, on which a carriage can be displaced in controlled fashion in the horizontal direction. Provided on the carriage are gripping elements that can be displaced in the vertical direction, by means of which individual pallets can be grasped, displaced in the vertical direction, displaced in the horizontal direction along the gantry by displacement of the carriage, and lastly set back down in the vertical direction.
An apparatus of a similar type is exemplified by German patent document DE-C-3 151 316. In such conventional handling apparatus, two controlled axes (NC axes) are needed in order to grasp pallets, displace them in the horizontal direction, and then set them back down. Such conventional handling apparatus have proven disadvantageous because they are relatively complex and costly. If, on the other hand, transport is to occur by means of only one NC axis, corresponding additional devices must be provided so that the pallets can be set down with the necessary accuracy, for which purpose ratchet devices, for example, can be provided. Such additional devices are, however, relatively complex and costly.
Furthermore, conventional handling apparatus which are suitable for pallet moving require a considerable amount of space, since in each case a gantry is required and accessible working space must be located within the gantry.
Yet another conventional handling apparatus is exemplified in DE 2,802,738 A1. This apparatus comprises two rocker elements which are arranged pivotally with respect to one another and which are positively coupled by a transmission for effecting a rotation of the second rocker element at a certain angular rate when the first angular rocker element is rotated at a fixed angular rate.
Such conventional apparatus allow an object to move along a locus curve, or locus of points defining a curve, in a horizontal plane, for instance, to feed a workpiece to a machine tool. However, the known apparatus do not disclose how the transmission between the two rocker elements must be designed in order to attain a locus curve having the shape of a square or a part thereof. In particular, conventional handling methods fail to disclose or to suggest any design principles which could be employed to obtain largely straight sections along such a locus curve. Furthermore, conventional apparatus do not allow for movement along a locus curve having horizontal and vertical sections.
For the foregoing reasons there is a need for a handling apparatus, which could be particularly suitable as a pallet moving apparatus, in which a single NC axis is sufficient to handle workpieces, especially pallets, in both the horizontal direction and vertical direction along largely straight lines. What is also needed is an apparatus which is as simple and space-saving as possible.
There is also a need for a handling apparatus which is capable of engaging a workpiece, a pallet or any other object and moving it along a locus curve having largely the shape of a square or a part thereof; that is, a locus curve which may have large linear horizontal and vertical segments or sections.